Method for manufacturing dislocation-free silicon single crystal

Abstract

A method for manufacturing a dislocation-free silicon single crystal, includes the steps of preparing a silicon seed crystal formed of a dislocation-free single crystal having a boron concentration of 1x1018 atoms/cm3 or more, preparing a silicon melt having a boron concentration which differs from that of the seed crystal by 7x1018 atoms/cm3 or less, and bringing the seed crystal into contact with the silicon melt to grow the silicon single crystal.

What is claimed is:  
     
       1. A method for manufacturing a dislocation-free silicon single crystal, comprising the steps of: 
       preparing a silicon seed crystal formed of a dislocation-free single crystal having a boron concentration of 1×10 18  atoms/cm 3  or more;  
       preparing a silicon melt having a boron concentration which differs from that of the seed crystal by 7×10 18  atoms/cm 3  or less; and  
       bringing the seed crystal into contact with the silicon melt to grow the silicon single crystal.  
     
     
       2. The method according to  claim 1 , wherein a Czochralski process or a Floating Zone process is used to grow the silicon single crystal. 
     
     
       3. The method according to  claim 1 , wherein a boron concentration of the seed crystal is 1×10 18  atoms/cm 3  to 7×10 18  atoms/cm 3 . 
     
     
       4. The method according to  claim 3 , wherein the boron concentration of the seed crystal is 3×10 18  atoms/cm 3  to 5×10 18  atoms/cm 3 . 
     
     
       5. The method according to  claim 1 , wherein the silicon melt is boron undoped. 
     
     
       6. The method according to  claim 1 , wherein the silicon melt contains at least one element selected from the group consisting of phosphorus, arsenic, and antimony.